Sound recording and reproducing apparatus



24, 1940- 1.. A. HERZIG SOUND RECORDING AND REPRODUCING APPARATUS Filed April 24, 1937 9 Sheets-Sheet 1 llllllllllllllllllllllll II A TTORNEYS.

Sept. 24, 1940. A. HERZIG SOUND RECORDING AND REPRODUCING APPARATUS Filed April 24, 1957 9 Sheets-Sheet 2 R o T N E v m Wz L 2 7724% ATTORNEYS Sept. 24, 1940. L. A. HERZIG' 2,215,468

I SUUND RECORDING AND REPRODUCING APPARATUS Filed April 24, 1937 9 Sheets-Sheet 3 ATTORNEYS Sept. 24, 1940. L..'A. HERZIG SOUND RECORDING AND REPRODUCING APPARATUS Filed April 24, 1937 4 A F" x 4/ 9 Sheets-Sheet 4 ATTO RNEYS Sept. 24, 1940. A. HERZIG SOUND RECORDING AND REPRODUCING APPARATUS Filed April 24, 1957 9 Sheets-Sheet 5 7 p 0- I L. A. HERZIG I 2,215,468

SOUND RECORDING AND REPRODUCING APPARATUS Filed April 24, 1957 9 Sheets-Sheet e ATTORNEYS b 1940. A. HERZIG 2,215,468

SOUND RECORDING AND REBRODUCING APPARATUS Filed April 24, 1937 9 Sheets-Sheet 7 .nlullillllllili WI: ll :i

lllnvllllllillln I u ATTO RNEYS Sept, 24, 1940. HERZlG 2,215,468

SOUND RECORDING AND REPRODUCING APPARATUS Filed April 24, 1937 9 Sheets-Sheet 8 &

INVEN I'OR [50/74/90 A AQflZ/ 0 .gm-m.

ATTORNEYS Sept. 24, 1940. HERZlG I 2,215,468

SOUND RECORDING AND REPRODUCING APPARATUS Filed April 24, 1937 9 Sheets-Sheet 9 y 4 EIQ j/EI/UEIUEIUU DUE] DU'EIEIEIIEI 1 1 I I I I I I I I I I I I I I I I I I I I I I I {1 I I I I I I1 I ATTORNEYS Patented Sept. 24, 1940 SOUND RECORDING AND R-EPRODUCIN APPARATUS Leonard A. Herzig, Brooklyn N. Y., assignor, by mesne' assignments, to Lon-Ga-Tone, Inc., New York, N. Y., a. corporation of New York Application April 24, 1937, Serial N0.'138,751

37 Claims.

This invention relates to a'photographic sound recording and reproducing system and has for its object to provide a new and improved apparatus for continuously and uninterruptedly recording on or, reproducing from a plurality of parallel sound tracks or for playing any selected part or track of the completed record.

Other objects of the invention are: to provide a new and improved photographic sound record; to provide a record in the form of a film having a, plurality of parallel sound record tracks thereon which are adapted to be played successively without audible break or extraneous sound during the change-over from track to track; to provide a record of the foregoing type in which the successive tracks are played by moving the film first in one direction and then in the reverse direction, and are joined to each other by uniform loops forming parts of the sound tracks; and to provide a record of this type in which the loops connecting the' sound tracks are exactly positioned and are all aligned in the same transverse section of the film.

Further objects of the invention are to provide a device of the above type having automatic reversing and step-up mechanisms to cause the scanning beam to follow the loops of the sound track during the change-over from track! to track; to provide an improved, highly sensitive reversing mechanism actuated by the film itself; to provide an apparatus of the above type having readily interchangeable recording and reproducing heads; to provide a novel and improved control for the scanning light; to provide a novel and improved system for shifting the beam without moving the lens assembly; to provide a novel and improved light source and lens system; to provide novel and improved driving and reversing mechanisms; to provide a high-speed rewind foruse in returning the film to starting position after playing individual selections or sections of the sound record; and in general to improve the details of construction and mode of operation of the parts in anapparatus of the 45 type referred to above. The invention is particularly applicable to apparatus for recording or reproducing sound for broadcasting purposes, for assemblies, for record libraries or for other purposes for which phonographs or film have heretofore been used. An important feature of the invention resides in the .use of a comparatively short film containing a plurality of sound tracks which are played successively. A standard width 35 mm. film may, I for example, have some thirty different sound v of driveshafts preferably having suitable vibramechanism is provided to selectively connect the attached to the film adjacent the ends of the trackswhich "are joined by loops so arranged that the scanning light follows the loops on the change-over without audible variation. The film is held on two reels and is fed first in one direction and then in the other for scanning each of 5 the different connected tracks which constitute.

the sound record. In one embodiment of the inventionthe film is fed past a sound gate by a pair of sprockets which are reversibly driven in unison. A pair 10 tion dampeners are continuously driven inopposite directions and an electrically operated clutch sprockets in driving relationship to the respective driveshafts. This mechanism is automat-,. ically operated by the film itself whenever the" end ofa sound track has been reached, or it may be operated manually. In the preferred form of the invention hereinafter described a sensitive and accurate control of the reversing mechanism is obtained by changing the grid potential of a space discharge tube by the capacity efiect of a conducting bar or strip which is formed in or sound tracks; the control being effected when the conducting strip reaches a predetermined"- point with respect to the sound gate.

Another feature of the invention resides in providing a scanning light and lens system for both recording and reproducing purposes, which supplies light of uniform intensity over the entire width of the film, and in shifting only the aperture plate transversely of the film to position the light beam for scanning the successive tracks of the film. In the recording head the aperture plate is preferably located between the light source and the lens system, while in the reproducing head the aperture plate is preferably located between the film and the photoelectric cell. In-either case the plate may be stepped from one position to the next by a mechanism which operates in synchronism with the revers= ing mechanism.

Another feature resides in the provision of a rewind mechanism for rewinding the film at a higher speed when single sound tracks or groups of tracks are to be used for individual selections. In one embodiment a manual switch is provided for stopping the film and for rewinding. The rewind is stopped automatically, however, when the conducting strip on the film reaches the designated point on the film gate. Means are also provided to prevent the rewind mechanism from. operating eiicept when the main drive clutches 56 friction wheel driven by a flexible driveshaft and brought into driving position by a rewind solenoid.

Another feature of the invention resides in the provision of an adjustable friction drive for the take-up mechanism which may be adjusted in accordance with the length of the film so that more power is supplied to operate the heavier reels when longer films are used. This adjustment is controlled by a dial which may be suitably graduated to read in feet of film.

Still another feature resides in the provision of a manual adjustment for the aperture plate which may be graduated to indicate the particular sound track being scanned. This adjustment permits any sound track to be selected from a multiple track film and is useful, for example, if different selections are recorded on the different tracks.

These and many other features and advantages of the invention will be described in connection with the accompanying drawings, in which:

Fig. 1 is a top plan view of my preferred apparatus as adapted for recording purposes;

Fig. 2 is a vertical section taken on line 2--2 of Fig. 1;

'Fig. 3' is a transverse section taken on line 3-3 of Fig. 1, showing the driving, reversing and rewinding mechanisms;

Fig. 4 is a detail section on line l-l of Fig.

3, showing the mechanical filter;

Fig. 5 is a horizontal section through the apparatus, taken on line 5-5 of Fig. 3;

Fig. 6 is an enlarged longitudinal section of the recording unit shown inFig. 1;

Fig. '7 is an electrical diagram of the recording unit shown in Fig. 6;

Fig. 8 is a view similar to Fig. 6, but showing the reproducing unit adapted to be used interchangeably with the recording unit of Fig. 6;

Fig. 9 is a detail section taken on line 9-9 of Fig. 8;

Fig. 10 is a circuit diagram of the reproducing unit shown in Fig. 8;

Fig. 11 is a sectional view taken on line |l-|I of Fig. 2, showing details of the mechanism for controlling the position of the aperture plate;

Fig. 12 is another-sectional view of said control mechanism, taken on line l2-|2 of Fig. 2;

Fig. 13 is a horizontal section taken on line I3l3 of Fig. 3, illustrating the sound gate and the threading and adjusting mechanism for the film;

Fig. 14 is a vertical section on line ll-l4 of Fig. 5, showing the rewind mechanism;

Fig. 15 is a detail section on line l5-l5 of Fig. 13, illustrating the parallel adjustment of the film guiding rollers;

Fig. 16 is vertical section on line Iii-l6 .of Fig.1 1, showing the mechanism for adjusting the tension of the take-up mechanism;

Fig. 17 is a view similarto Fig. 13, showing a modification of the film driving mechanism;

Fig. 18 is a plan view of a strip of film, showing the electric contacts at both ends for controlling the reversal of the film; and I Fig. 19 is a diagram of the electrical circuits of the apparatus.

are released. In' the form shown herein for pur- 'poses of illustration the rewind is effected by a to be given as broad an interpretation as the state of the art will permit.

The machine shown in the drawings comprises a top plate I (Figs. 1 to 3) on-which are mounted a pair of reels 2 carrying the film 3 which contains the sound record. This film may be of the usual type employed in motion pictures and is shown more in detail in Fig. 18 as having a plurality of parallel sound record tracks 4 which extend over substantially the entire length of the film and are joined at their ends by loops 5. The successive tracks are recorded with the film moving in opposite directions so that a continuous sound record is obtained by following the tracks in succession and reversing the film as the end of each track is reached. The film has the usual perforations 6 which cooperate with suitable teeth on the drive sprockets and is provided adjacent its two ends, at predetermined points with respect to the loops 5, with strips 1 of conducting material which may be sprayed or painted on the film or may be formed separately and attached thereto in any convenient way.

The conducting strips 1 are used for automatically reversing the film 3 in a manner hereinafter described. It is to be understood that the film itself may be of any suitable or standard construction. The sound tracks 4, however, are all of exactly the same length and the loops 5 are aligned in the same transverse section of the film so that the scanning ray can be caused to exactly follow these loops on each reversal of the film. This exactness in the position of the various loops is obtained by the control mechanism hereinafter described.

Referring again to Figs. 1 to 3, the film 3 is passed between the reels 2 over a pair of drive or feed sprockets l0 and over a film gate H. Suitable spring-pressed guide rollers.l2 or equivalent means are provided to take up the slack of the film and to absorb the shock of reversal as hereinafter described. Idler rollers l3 and H are provided for suitably guiding the film with respect to the feed sprockets l0 and the film gate II.

The film gate ll supports the film in a position to be scanned by light from a light source [5 which is focussed by a telescope or lens system l6 onto the film. The film gate ll, adjustable idler rollers I3, light source 15, telescope.-

I6 and associated mechanisms are mounted as a unit on a panel l8 which-is adapted to be removed from the top plate I and to be replaced by a reproducing unit when the machine is used for reproducing sound from the film.

Take-up mechanism The take-up mechanism for driving the reels 2 is shown in detail in Figs. 2 and 5 and includes a motor 20 which is mounted on suitable brackets 2| supported on the base 22 of the machine. The motor 20, through a reduction gear 23, drives pulleys 24 in opposite directions. These pulleys carry belts 25 which drive the pulleys 26. Each pulley 26"is mounted on a sleeve 21 which is rotatably held in a bearing 28 supported by a bracket 29 which is attached to the top plate I of the machine. Each sleeve 21 carries a disk 30 on which a friction disk 3i of suitable friction material is supported as shown in Fig. 2. Engaging this friction disk 3| is a driven disk 32 'which is keyed, as by key 33, to a shaft 34 which extends through the sleeve 21 and is rotatable therein. The shaft 34 extends through a bearing 35 which-is formed on the bracket 29 and supports a reel 2. The reel is locked to shaft 34 for rotation therewith 'by' means of a lever 36'which is adapted to fold over onto the top of the reel for the above purpose.

For varying the amount of friction I provide a pair of'pivoted arms 48 which are pivoted at 4| to ears 42 carried on the top plate I of the machine. Each arm 48 is provided at one end with afork 43 carrying adjustable pins 44 which seat in a rotating collar" 45. A spring 46 is seated around the shaft between the collar 45 and the driven disk 32 to apply pressure to saiddisk 'dependent upon the amount of' compression of said spring. The otherends' of the arms 48'are con-- nected by pins 58 to a collar 5I which is carried" on shaft 52 extending through a bushing 53' attached to the top plate I of the machine. The shaft 52 is provided at its ends with threads'54 as shown in Fig; 16 An adjusing knob55'is attached by screws 56 to a threaded collar 51 which each lower disk 38 is driven by a belt 25 from a' pulley 24 which in turn is driven by the motor 28. The lower disk 38 drives the upper disk 32 by the friction obtained by the pressure of .the spring 46. The disk 32, being keyed to the shaft 34, drives the shaft and the reel 2 which is attached thereto. If desired, an index may be provided by mounting a disk 68 at the. end of the shaft 52 within the knob 55 and visible through a slot 6| in saidknob as shown in Fig. 16. The

disk accordingly moves axially and, by its posi-- tion, indicates the adjustment of the springs 46.

.A suitable scale may be provided on the knob 55 to register with the disk 68 for theforegoing purpose.

It has been found that the driving force required for the reels 2 depends upon the weight of the reels, more force being required for driving a heavy reel than for alight reel. This weight is proportional to the length of the film, consequently the adjusting knob 55 may be graduated directly in feet of film so that an operator, knowing the feet of film on any given reel, can adjust the pressure of the spring 46 accordingly. It is to be understood thatthe take-up mechanism 0perates to supply suflicient force to the reel to maintain thefilm in a tight condition while it is being driven by the feed sprockets I8 so as to feed the same from one reel to the other.

Drive for feed sprockets Feed sprockets I8 are driven from the-motor 28 by means of a driveshaft attached to the motor, (Figs. 2, 3 and 5) and carrying a flywheel 66 by which irregularities in the drive are largely eliminated and hunting'of the motor is prevented. The shaft 65'is connected by a flexible coupling 61 to a helical gear 68 which drives a pair of helical gears69 at the same speed-and in opposite directions. The gears 69 are rotatably mounted on sleeves I8 which are journaled in bearings II carried onbrackets 12 which are attached to the top plate I and the base 22 of the machine in a convenient manner. The gears 69 each carry a sprocket I 8.

spider I3 havinga plurality of arms"l4 (as"sho wn' 111mg. 4) which are connectedby springs I6 to pins' l6' which are formed'onorattached to flywheels 1]. The flywheels" are attached to the sleeves "IO -and-are each attached to asleeve I8 which is part of the lower. tooth element 19 of a one-way clutch "88". I The upper tooth element 8I' of this clutch S88 is part of sleeve 82 which isjournaled in 1bearings'83 carried by the. bracket I2. Eachsleeve 82'carriesagear 84 meshing with a gear 85*which isattached'to the shaft 86 on'which the drive'sprocket I8 is fixed. The two gears'85 are preferably split gears'of any suitable type designed to eliminate backlash or play; and' these 'ge'arsa're connected byan idler gear:

81 was to'oper'ate in'un'ison and at-auniform speed.

For operatingvtheclutclrmember 88 there is provided a rod 98"which extends through each sleeve I8 andiis providedwith a collar. 9Iwhich is, p'ositionedbelow'the upper tooth element 8| of the clutch 88" and is adapted when-elevated to raise the upper tooth element sufficiently to disengage the tooth from thelower element I9. The

rods 98 are'connected'to a' pivoted arm 92 which is pivoted at 93"between the arms of adouble "bracket 94'supported onthe base 22asshown in Fig. 3. The-bracket also providesbearings 95 in which the driveshaft-65'isjournaled as shown in Fig. 2. I

The ends of the arm Mare-attached to cores 98"of solenoids" 99 which are arranged to'controlthe position'of the. arm 92. The arrangement is such that when oneof the solenoids 99 is energized the core '98 and the rod 98 attached thereto are pulled downwardly, thereby causing thecorresponding clutch 80-to engage while disengaging the opposite clutch. The direction of drive of the sprockets I8 is 'accordingly dependent upon the particular solenoid 99 which is energized at any particular time. wheels 11 are rotated continuously. When one .of the clutches isdisplaced,:however, the corresponding driveshaft picks up and drives the The springs"|5 provide a loose coupling between the respective'ilywheel I1 and the associated ge'arfl so that each spider forms a mechanical filter or vibration dampener to eliminate minor vibrations or variations in the drive from being applied to and eflecting the uniform rotation of the feed sprockets I8. By interconnecting the driveshaft for the two feed sprockets I8 by meansof the gear 81 any play or lost mo- The motor 28 and the fly-.

tion is prevented and the gears are caused to opquiring' the solenoid to be continuously energized,

a suitable holding means may be provided. In the embodimentshown, this holding means may comprise electromagnets I88 which are suitably mounted on'the frame of the machine andcooperate witharmatures I8I' carried by the pivoted arm 92 as shown in Figs. 3 and 19. The operation of electromagnets I88'will be described later.

High speed rewind mechanism In certain instances it is desirable to rewind the reel at a higher rate of speed, as for example I24 of a solenoid I25.

when the various film tracks are used for independent selectionsor programs. In that event when one selection has been completed it may be desired to rewind the film preliminary to playing a second selection. This may be accomplished by providing a high speed rewind, one form of which is shown in Figs. 3 and 14. In the embodiment shown the rewind comprises a flexible driveshaft I08 which is driven by a gear I09 meshing with one of the helical gears 69. The flexible driveshaft I08 is attached in driving relationship to a friction disk I I which is adapted to be brought into driving engagement with a second friction 'diskI II which is mounted on the shaft 86 of the corresponding feed sprocket I0 which is normally driven by the gear 69 from which the power is taken; The friction disk I I0 is mounted on a housing II2 which is attached by a block II3 to the flexible driveshaft I08 and is mounted for rotation on a shaft II4 by means of a collar H5. The shaft H4 is pivoted at II6 to ears II1 attached to the top plate I of the machine. The pivotal position of the shaft H4 is determined by an arm I20 having a forked end I2I which is adapted to be clamped by a screw I22 about the arm H4 and at its other end is attached to a rod I23 which engages the core The arrangement of the above parts is such that when the solenoid I25 is energized the core I24 and the rod I23 are pulled downwardly thereby pivoting the arm I20 and the shaft H4 and causing the friction disk IIO to bear against and drive the friction disk III. When the solenoid I25 is deenergized, the disk H0 is brought out of engagementwith the disk I I I by the resilience of the flexible drive I08 -or by any other suitable means not shown.

For holding the arm 92 in neutral position with both clutches 80 disengaged, when the machine is to be stopped or when the high speed rewind mechanism is to be used, two springs I30 balance the arm 92 as shown in Fig. 3.

Recording head The recording head is mounted as a unit on the panel I8 as shown in detail in Fig. 6. This recording head carries an elongated glow lamp I4I comprising the light source, a telescope tube I6 and the film gate II together with associated mechanisms hereinafter described. The film gate I I comprises a circular housing I45 mounted in a cup I46 which is attached to the panel I8 by suitable means such as screws I41. A pair of rotating rings I48 and I49 are mounted on the housing I45. These rings are provided with shoulders I50 and II respectively, between which the film 3 is seated. The housing I45 is also provided with opposite apertures I52 and I53 which are aligned with the scanning ray hereinafter described. The aperture I52 permits the focus of the light ray on the film to be properly adjusted, while aperture I53 permits visual inspection of the focussing operation. In the form shown the lower ring I48 is mounted for rotation directly on the housing I45 and is provided with a lip I54 which is seated between the shoulder I55,

formed in the housing I45 andthe surface of motion of the ring I48. 7

The upper ring I49 is shown as insulated from the housing I45 for a reason to be described. For this purpose the upper ring is attached to' an inner rotating ring I60 from which it is separated by a ring I6I of insulating material. The ring I60 is mounted for rotation on the upper part of the housing I45 and is provided with a flange I62 which bears against and is confined by a flange I63 formed on a locking ring I64 which is attached to the housing I45. A helical spring I65 is seated in a suitable recess in the housing I45 and bears against the top of the flange I62 to prevent axial movement of the ring I49. The flange I63 is spaced from the .ring I49 so as to avoid making electrical contact therewith. The ring I49 is-thus insulated by the ring I6I from the housing I45. For making an electrical contact with this ring a spring brush I is provided which bears against the surface of the ring I49 and is attached to the locking ring I64 by means ofan insulating bushing I1I. An electrical connection may be made to this brush I10 which is fastened to the ring I64 by screw I12. It will be noted that the film 3 is supported on the rings I48 and I49 as it passes over the housing I45 constituting the film gate 1| and is thereby held in proper position to receive the scanning ray.

The glow lamp MI is preferably formed with elongated electrodes I and I16 as shown in Fig. 7. These electrodes are made substantially longer than the area of the film 3 which is to be scanned so that light may be focussed over the entire width of the film with substantially equal intensity. In the form shown the electrode I15 is channel-shaped and constitutes the cathode, whereas the electrode I16 is in the form of a looped wire registering with the edges of the channel-shaped electrode I15 and. constitutes the anode. This elongated construction permits a uniform light intensity to be radiated from a substantial portion of the glow lamp. This light is focussed by asuitable lens system carried by the telescope tube I6 over the entire width of the film 3. In the form shown the telescope tube l6 carries a pair of cylindrical lenses I18 the axes of which extend in a direction transverse to lens I19 and are arranged so as to concentrate the rays received from the glow lamp I4I over an area extending the full width of the film 3. This light is concentrated and focussed in a narrow vertical band by means of the cylindrical lens I19 which is arranged with its axis extending in a vertical direction. The arrangement is such that this band which constitutes the scanning ray is preferably not over .0003" in width. The telescope tube I6 may be provided with a lug I80 which is adjustably supported on a screw I8I' which is held in bracket I82 attached to the panel I8. Adjustment of the screw I8I moves the telescope tube and the entire lens system axially so as to permit proper focussing of the light rays from the glow lamp I4I.

In order to confine the ray to one sound track of the film at a time an aperture plate I85 is provided betweenthe glow lamp MI and the telescope tube I6. This aperture plate is formed. with a narrow slit I86 corresponding in width to the width of one of the sound tracks as indicated in Figs. 6 and 12 and is mounted for sliding vertical movement in a shield I81 which is carried by the telescope tube I6. The aperture plate I85 is provided with a downwardly extending portion I88 carrying rack I89 which meshes with a gear I90. The gear I90 is adjustably fastened to a shaft I9I which extends through the front wall I92 of panel I8 and carries a knob I93 by means of which the position of the aperture plate I85 may be adjusted. It will be noted that the gear I90 is sufliciently long to,.permit slight axial movement of the rack-I89 as the aperture plate I85 and telescope tube 16 are adscribed above. f For shifting the aperture plate I85 between Y successive film tracks a pawl and ratchet mechall anism is provided which comprises a ratchet gear I98 (Figs. 6 and 11) carried on the shaft I9I and held between bearings I98 of said shaft which are carried in bracket 200 attached to the panel 18. A pawl 20I is pivoted to a split arm 202 which is journaled on the shaft I9I on opposite sides of the ratchet gear I98 as shown in Figs. 5 and 11. The pawl 20I rests against an adjustable stop 204 (Fig. 11) which is carried by an arm 205 (Fig. 5) attached to the bracket 200.

The pawl 20'I is normally held out of engagement with ratchet gear I98 by a spring 206. A locking pawl 20! is pivoted as at 208 on an arm 209 attached to the bracket 200 and is moved toward the ratchet wheel I98 by a spring 2I0. Ad-

justable stop 203 is carried by the arm 202 to engage the locking pawl 20! and hold the same out of contact with the teeth of the ratchet wheel I98 when the wheel is not actuated. Thearm 202 is attached to core 2 of' a solenoid 2I2 which is adapted when energized to cause the pivotal movement of the arm 202 for stepping the ratchet wheel I98 around one tooth. Suitable means, such as a spring 2I3, may be provided for returning the arm 202 to the position shown in Fig. 11 when the solenoid is deenergized.

For holding. the ratchet wheel I98 in a given position a disk 2I5 (Figs. 6 and 1 is mounted on the shaft I9I and is provided with a plurality of peripheral teeth 2; against which rollers 2" rest. These rollers are carried on leaf springs 2I8 which are attached to the panel I8 by means of screws 2I9. The rollers 2" are adapted to engage the disk 2I5 between the teeth 2 I6 so as to secure the ratchet mechanism in any adjusted position. Itis to be noted that when the solenoid 2I2 is deenergized the arm 202 is in the position shown in Fig. 11 and the pawls 20I and 201 are held out of engagement withthe ratchet wheel I98 by the stops 204 and 203, respectively. The shaft I9I may then be rotated by means of knob I93. This knob is preferably provided with graduations 220 which register with a suitable index on the front I92 of panel I8 to indicate the position of the aperture I88. This index may, for example, be numbered to indicate the number of the sound track which is in position to be played or recorded. This hand adjustment may be used, for example, when it is desired to set the machine to record on a given sound track. The dial likewise turns with the shaft I9I during the automatic operation of the machine and thereby indicates the position of the scanning ray at any particulartime.

It is to be understood that the entire ratchet mechanism including the solenoid 2I2 may be removable as a unit with the panel I8. Suitable quick detachable plugs, not shown, may be provided for breaking the electrical circuit when the recording head is thus removed.

As shown in Fig. 6, a shield 225 having an aperture 226 in alignment with the telescope tube I6 may be positioned over the glow lamp I to prevent light rays from going any place except through the apertures 226 and 234, the latter of which is used for monitoring purposes as shown in Fig. 1 and as described below. This shield may have suitable spring clips 22'! by which it is securely seated over the glow lamp.

7 other.

The glow lamp may be provided with a suitit is connected to a supply circuit in the usual manner.

The glow lampis actuated as indicated in Fig. 7 by the output circuit of an amplifier 230 which is fed in the usual manner by a microphone 23l or by any other suitable pickup means.

In order to assist in listening in, a photoelectric cell 233 is mounted on the panel I8 as indicated in Fig. 1 in a position to be energized directly by the glow lamp ML The shield 225 is provided with a slit 234 opposite the photoelectric cell 233 as shown in Fig. 1 so as to permit rays .from the glow lamp to pass therethrough. The

photoelectric cell 233 is preferably made with elongated elements 235 which extend in an axial direction substantially coextensible "with the elongated elements I15 and I16 of the glow lamp I4I. This photoelectric cell 233 may be connected with the input circuit of a standardamplifier 238 the output circuit of which may be able vibration dampening socket 228 by which within the telescopetube I6 may be varied as desired. Ingeneral the optical system should be. designed to focus the light in the form of a fine vertical band equal to the entire width of the film'so that the aperture plate in moving vertically can cut off all of the light except that corresponding to the selected sound track. In this way it is only necessary to move the aperture plate in shifting from-one sound track to an- The remainder of the mechanism remains stationary. In the embodiment shown an upward movement of the aperture plate will cause a downward movement of the scanning ray at the film and vice versa. The lens system, however, could be arranged to produce parallel rays in which case the movement of the aperture wouldcorrespond. to the movement of the scan-' ning ray at the film.

In the above-described mechanism the scanning rays may be shifted from one sound track tothenext with great rapidity inasmuch as it is .only necessary to move the comparatively light The movement can also Reproducing head The machine is so constructed that'the reproducing head shown in Fig. 8 is interchangeable with the recording head shown in Fig. 6. The reproducing head comprises a panel 245 which is adapted to seat on and be secured to the top plate of the machine in place of the panel I8 as shown in Fig. 1. This panel 245 carries a cup 246 which is attached thereto by suitable screws 241 andsupports a housing 248 which forms the film gate. The housing 248 is provided with a cylindrical bore 249 in which the photoelectric cell 250 is adapted to be posi- "tioned. It is also provided with an opening 25I which extends over substantially the entire width of the film so that the rays from the various sound tracks can pass to the photoelectric cell.

provided with a flange 256 which engages beneath a shoulder 251 in said housing for positioning the ring.

The ring 253 is mounted on a ring 258 from which it is separated by an insulating ring 259.

The ring 258 is rotatably mounted on the hous- A ing 248 and is provided with a flange 268 which is engaged by the flange 26l formed on a locking ring 262. The spring 263 is employed to keep the film guide flange 255 in constant contact with the upper edge of the film 3 during operation even though wear should take place.

The flange 26I terminates short of the ring 253 so that this ring is electrically insulated from the housing. Contact is made to the ring 253 by means of a flexible brush 264 which is attached to an extension 265 of the housing and is insulated therefrom by bushing 266. The extension 265 carries a cap 261 which closes the top of the housing and forms a socket for making the electrical connection to the photoelectric cell 258. The socket may be of any convenient or standard construction for this pur-' pose. Suitable spacing elements 268 of soft material such as rubber may be provided at the bottom of the housing 248 and within the central bore 249 so as to support the photoelectric cell 258 and to prevent vibration from being imparted thereto.

The housing 248 is also provided with a vertical bore 218 in which an aperture plate 21l slides. The aperture plate is provided with an aperture 212 of a suitable dimension to pass light only from one sound track of the film at a time.

I The photoelectric'cell is formed with a pair of elongated electrodes 213 and 214, as indicated in Fig. 10, so that the effect of the scanning ray on the film is unchanged as the ray moves across the film.

The aperture plate 21l carries on its lower end a rack 216 which engages the gear 211 held on the shaft l9l'. The shaft I91 corresponds to shaft l9! shown in Fig. 6 and carries similar ratchet mechanism which has been given corresponding reference numerals with primes affixed thereto, and the description of these parts will accordingly not be repeated. It is to be understood that the entire ratchet mechanism of Fig. 11, including the arm 282, the solenoid M2 and associated parts is duplicated in the reproducing head of Fig. 8 and this reproducing head is removable as a unit to replace the corresponding mechanism in the recording head.

The reproducing head is also provided with a socket 288 in which exciting lamp 28l is held. This exciting lamp is provided with an elongated filament 282 as shown in Fig. 10, which is of such length that rays of equalintensity are propagated over the entire apertured area of the tele- .scope tube to be described. This filament 282 'may be held in position bya spring 283 which is adapted to maintain the filament tight under all'conditions. This is important inasmuch as the image of the filament is to be focussed onto the film and any variations thereof would cause corresponding distortion in the reproduction.

The reproducing head is provided witha telescope tube l6 which is similar in const uction to the telescope tube 18 of Fig. 6 and carries a suitable lens system. The elements of the tube and the lens have accordingly been given the same reference characters with prin'ies afiixed thereto and a description thereof will not be repeated.

The lenses in general are adapted to focus an image of the elongated filament 282 on the film 3 as the film passes the opening 25! in the I housing 248. The image must be of equal intensity across the entire width of the film inasmuch as it is to cooperate with the various sound tracks thereon. The aperture plate 21l cuts off all of the rays passing through the film except the rays through the selected sound track which are permitted to pass through the aperture 212 and to be impressed upon the photoelectric cell 258. As the aperture plate is stepped upwardly or downwardly by means of the ratchet mechanism the scanning ray is thus shifted from one sound track to the next in a manner similar to that described in connection with the-aperture plate I of Fig. 6. In the reproducing head, however, the scanning rays are continuously applied to the entire film width and the aperture plate is positioned between the film and the photoelectric cell. It is to be understood that the aperture plate could be placed in some other position if desired. For example, the aperture plate could be located between the exciting lamp 28I and the telescope tube as shown in Fig. 6, or it could be located between the telescope tube and thefllm 3.

Guide rollers Referring to Fig. 1, it is noted that the spring- "pressed guide rollers l2 are provided for absorbing the shock on the film during reversal. Each of these guide rollers is shown as mounted on an arm 288 which is pivoted by means of a screw 289 and is held by a spring 298 in contact with the film 3. Stop 29! may be used to limit the movement of these arms. The adjustment of the spring tension should be such that the rollers l2 are adapted to take up the shock when the film is reversed and prevent tearing of the film. It is to be noted in this connection that when the film is reversed one of the reels 2 will be full and correspondingly heavy and will be rotating in a direction to wind up the film thereon. When the film is suddenly reversed by reversal of the-- sprockets lo, the inertia of this full reel must be overcome and the reel started to rotate in the opposite direction against the drag exerted by the take-up mechanism. The pressure of the springs 298 is adjusted so as to accomplish this. the arms 288 swinging inwardly as the film tightens, and these arms are returned by the springs 298 when reversal occurs in the direction of the reel for taking up. It is to be understood that suitable adjustment may be provided for varying the pressure of the springs 298 if desired.

Idler rollers 14 are mounted in the usual manner to hold the fllm in contact with the drive sprockets l8. Idler rollers l3 are mounted between the feed sprockets l8 and the film gate in which these idler rollers are attached to hold the film in contact with the feed sprockets and also to maintain the film in engagement with a predetermined sector of the aperture plate as shown more in detail in Fig. 13. In Fig. 13 idler rollers l3 are shown mounted so that they may be adjusted to compensate for variations in length of the film due to temperature changes, etc., the mounting being arranged so that this adjustment can be efiected wlthoutchanging the.

arc of contact of the film with the film gate. This latter feature is of importance inasmuch as the reversal of the film is automatically effected when the conducting strip '1 thereon engages'the film gate; consequently any variation in the arc of contact would alter the timing ofthe control attached to the panel 13 in the case of the recording head, or to the panel 245 in the case of the reproducing head. A bushing 293 is disposed about the shaft 295 and is adapted to be clamped against the plate 291 by means of a thumb screw, 299. The roller 13' is mounted for free rotaflqn on this bushing 233.

The slot 296 is elongated in a direction parallel to the line of feed of the film toward the film gate, that is, in a direction parallel to a tangent to the film gate at the point where the conducting strip 1 on the film comes into contact with the film gate as shown in Fig. 13-. Consequently' adjustment of the idler roller 13 along this slot 296 does not change the angle of the feed 'ofthe film past the sound gate and does not change the timing of the control mechanism. It is to be understood, of course, that other suitable ad justing means may be used if desired in place of that shown and described above.

Film drive of Fig. 17

Fig. 17 .shows a modified form of film drive which may be .used in place of the two feed sprockets 10. In this embodiment the film gate 11 is constructed in the manner described above.

In place of the two feed sprockets 10, however,

there is provided a single feed sprocket 305'whichis of suflicient diameter so that the film may con.-

tact over twoseparate portions of the surface thereof. This sprocket 305 is driven by gear 306 which meshes with the gears 35 as shown in Fig. 1'7. The film 3 passes in driving engagement with a portion of the surface of the feedsprocket 305 with which it is held in ,contactby adjustable rollers 30'1. Thence the film passes around the film gate H and in driving engagement with another portion of the sprocket 305 with which it is held in contact by adjustable rollers 308. The rollers 301 and 308 are mounted so that they can be displaced to permit the film to be threaded over the sprocket 305. In this embodiment the film is driven to and from .the film gate by means of a single sprocket. This construction may be preferred in certain instances as for example in a light machine where it is desired to reduce the number of parts as much as possible. It is understood that' the machine is otherwise similar to that described above.

Control circuit 314 of standard construction such as a grid glowtube. A relay 315 is connected in series with one of the leads from the secondary 313 to the tube 314 in such a way that the space current of. the tube passes through relay 315 and energizesthe When the;capacityhereinafter described is added to'the grid circuit, however, the potential of the grid isaltered sufiiciently to permit passage of space current through. the tube. For this pur: pose the grid 311 is connected to an insulated ring 149 of the recording head or the insulated ring 253 of the reproducing head by means of the respective contact brushes 110 and 264.

The bottom'ring 133 ofthe recording head or the bottcm ring. 252 of the reproducing head is grounded to the unit. Consequently. when the metallic strip '1 of the film engagesthese rings the effect is to add capacity -to the grid circuit thereby changing the, gridbiasing potential and" permitting s ace current to how. This space currentxenergizes relay 315 which thereupon attracts its armature and closes'its contact 325,

completing the circuit from one side of the supply line 310 through an impulse relay 32'Iand back tothe other'side of the supply line. The

. relay 321 is thus connected across the line and is energized thereby The relay 321'isof the im-' pulse type whichis 9 .da'jite'd to move its armature 323 alternately to close contact 329 or 330 at suc cessive actuations of the relay.

A switch such as a push button 320 may be connected in parallel to the contact points 325 of relay 315 by which the electrical circuit may be manually operated to actuate the relays when desired. The contacts 329 and 330 are connected respectively to blades 332 and 331 of a triple-pole triple-throw switch 333. The armature 323 is connected by a line 33,4 to one side of the supply line. Contacts 335 and 333 of switch 333, which cooperate with the blade 331, are connected together and to one of the solenoids 93 as well as to a-suitable rectifier such as a rectox unit 331 which is connectedto a holding electromagnet 100. In the embodiment shown these "contacts are connected to the right hand solenoid 93. The circuit of this solenoid is completed through a contact 331 engaging an arm 333 carried on the arm 92. The arm 338 is connected by a lead 339 to the opposite side of the supply line. The left hand contact 340 for the blade 332 is connected to both a rectox unit 31i3 which supplies the holding electromagnet 100 on the left side of the arm 92, as well as to the left hand solenoid 99 and thence through lead 341 to a lower contact 342 which is adapted to be engaged by the arm 333 when the 'arm 92 has been depressed by actuation of the right hand solenoid 99. When' starting the machine the arm 92 is in a neutral position due to the balancing springs 130, which allows the clutchesto remain in neutral position. The motor 201s then started and allowedto come up ,to speed. Thereafter the switch 312 is closed to energize the control circuit. 7

The switch/312 has amake, break, and then make circuit whereby in the event that the arm 32 of impulse'relay 321 is not closing contact 330 an impulse will ,be transmitted through contact arm 365 and impulse relay 321 causing arm 323 to close contact 330' for starting purposes. This safety factor insures that arm 323 will always be in the correct posltionfor moving the film in the one direction at starting time. The arm 328 is now making contact with contact 330 on grid 3" of tube 3 is altered thereby allow-- ing space current to pass. This space current passing through relay 3 I 5 energizes the same and causes the relay to close contact 325 thereby completing the circuit through and energizing the impulse relay 321 to shift the arm 328, thereby opening contact 330 and closing contact 32 9.

The contact 329 supplies current through blade 332 and contact 340 of switch 333 to the rectox unit-353, which I shall refer to as a'holding current, and also to the left-hand solenoid 99, the circuit to which is completed through contact 342 and arm 338. Energization of the left-hand solenoid 99 pulls the left end of arm 92 downward, thereby reversing the drive ofthe machine in the manner described in connection with Figs. 3 to'5 and at the same time opening contact 342 and closing contact 331. The left-hand solenoid 99 is accordingly energized only momentarily and is deenergized as soon as it hasbeen' actuated to shift the arm 92. However, holding current supplied through rectox unit 363'is supplied to the associated electromagnet I (was shown in Fig. 19.

The film is now running in the'reverse direction. and, when it has again reached the end of its travel so that the opposite conducting strip 1 contacts with the above-mentioned rings on the film gate, a circuit is again completed which energizes relay 3l5 and thereby again energizes impulse relay 321. This energization of relay 321 opens contact 329 and closes contact 330, thereby completing the circuit through blade 33l of switch 333 to the rectox unit 36l as well as to the right-hand solenoid 99, -contact'331 now being closed. This energization of the right-hand solenoid 99 again actuates :arm' 92, reversing the position thereof and reversing the direction of drive in the manner described above. It will be noted, therefore, that each successive engagement of the conducting strips 1 with the rings of the film gate causes reversal of the drive. In order to actuate the ratchet mechanism in synchronism with the reversal of drive, the solenoid N2 of Fig. 11 is connected to one side of the supply line by lead 339 and thence by contact 345 to the third blade 346 of switch 333 which is connected by lead 341 to contact 325 of relay 3i5. Each energization of relay 3i5 which closes contact 325 accordingly completes the circuit through solenoid H2 and causes the ratchet mechanism to step the aperture plate to its next position. The shifting of the aperture plate on the reversal of drive is accordingly accurately synchronized so that, in recording, the successive sound tracks are joined by uniform loops as shown in Fig. 18, and, in reproducing, the scanning ray follows the path of these loops as it is shifted from one sound track to the next. -In

this way any break in the sound is avoided. The.

different selection may, for example, be recorded on each sound track. In this event the tracks may all be recorded in the same direction and when the selection has been completely played it is necessary to stop the machine and rewind the film prior to the playing of the next selection. By means of the connections shown in Fig. 19 the film may be stopped for the above purpose by shifting the triple-pole switch 333 so that blades 33l and 332 engage the second contacts. The second contact 350 is not connected to any electric circuit. Therefore, when arm 328 engages contact 329 no electrical circuit is made through blade 332, hence rocker arm 92 is moved to a neutral position by means of springs i 30 causing the clutch mechanisms to disengage and bringing the film to a dead stop. However, in

the event the record referred to above is a short record and manual operation is desired to stop this record from running to the end of the film, push button 320 may be used to energize impulse relay 321 so that the above-mentioned circuit is opened. It is to be noted that contact 331 is closed while the arm 92 is in neutral position and when the right end of arm 92 is in elevated position. The machine can thus be'alternately started and stopped by button 320.

In order to actuate the high speed rewind, the rewind solenoid I25 is connected from one side of the line to lead 339 through a switch, to a third contact 352 adapted to engage the blade 332 of switch 333. 'After the machine has been stopped in the manner describedabov'e, switch 333 is shifted to a third position to close contact 352 thereby completing the circuit from contact 329 through blade 332, contact 352 and switch 35i, to the solenoid I25, thu causing the rewind mechanism shown in Fig. 14 to be actuated for rewinding the film. The switch 35I is associated with an arm 353 which is carried by arm 92 and is adapted to open the circuit whenever arm 92 is out of neutral position, thereby preventing accidental operation of the rewind mechanism when either of the clutches is engaged.

In order to automatically stop the machine when the film has been rewound, the conducting strip 1 actuates the relay mechanism as described above, thereby opening the electrical circuit so that no current can pass to any solenoid, and allowing the balancing springs 130 to bringarm 92 to neutral position. If switch 333 is then returned to its second position the arm 33! closes contact 336 thereby energizing the right hand solenoid 99 and causing the machine to again operate. The machine will then operate until another impulse closes contact 329 of impulse relay 321 which then opens the electrical circuit through blade 332, allowing arm 92 to again be neutralized by springs I30.

Summarizing the above, it is noted that with switch 333 in the position shown in Fig. 19 the machine is automatically reversed at each end of the sound track by contact strip 1 and is adapted to continuously play the entire sound track. With switch 333 in the second position the machine is alternately operated in one direction by energization of the right-hand solenoid 99 when contact 330 is closed, or is stopped by deenergizing the circuit when contact 329 is closed allowing neutralizing springs I30 to neutralize rocker arm 92. With switch 333 in the third position the high speed rewind mechanism is operated when contact 329 is closed to complete a circuit through solenoid I25 and the machine is stopped when contact 330 is closed to deenergize the circuit allowing springs I30 to again neutralize rocker arm 92. I

It is evident, therefore, that any desired com -bination of manual and automatic control can be obtained by the above-described system. It

is further to be understood that only so much' of the circuit has been set forth as is necessary to an understanding of the invention. Various condensers are connected across the relay con- .tacts in the usual manner to prevent sparking.

Other control and adjusting features may be incorporated therein in a manner understood in the art.

- Operation The operation of the various elements has been described above. It is to. be noted that the and reproducing heads, both of which are mounted as a unit and may be removed from .the machine with a minimum amount of labor and time. The film is fed from one reel, over the drive sprockets and film gate and onto the opposite reel. The drive sprockets III are actuated in unison by the driving mechanism shown in Figs. 2 to 5, the direction of drive being controlled by the position of arm 92 which actuates the clutches 80. With arm 92 in neutral position the machine is stopped. With arm 92 tilted either upwardlyor downwardly the film is fed in a direction dependent upon the particular clutch which is engaged thereby.

It is to be noted that the light source, telescope tube and associated parts are stationary, the aperture plate being moved to shift the position of the scanning ray. The aperture plate is moved by the ratchet mechanism shown in Figs. 6, 8, 11 and 12 so as to shift the scanning ray from one sound track to another at each actuation thereof. This ratchet mechanism is controlled by asolenoid which is connected in parallel to the solenoid controllingthe reversal of feed, consequently exact synchronism is assured.

While the film gate is shown as having rotating rings it is obvious that stationary rings could be used if desired, in which case one of the rings would be insulated from the machine and the other grounded thereto so that a circuit would be completed by contact strips I for actuating the control mechanism whenever these strips engage the appropriate part of the sound gate. It is also evident that the sound gate may be of other construction and shape. A round gate has been shown for convenience inasmuch as it is adaptedto receive the photoelectric cell and also to serve as a guide for the film. In some instances it may be desirable to omit part of the housing in which case the photoelectric cell can be mounted in back of the film gate. The details of construction and mounting of the telescope tube and the lens system may also be varied as desired. In Fig. 6 a particular mechanical connection has been shown for permitting the aperture plate to be shifted with the telescope tube while maintaining driving engagement with gear I90. but it is evident that any other suitable driving connection which permits of this relative M l 5 ment may be employed,

Although certain details of construction and combination of parts have been specifically shown and described forpurp'oses of illustrating the in- -'vention it is to be understood that various changes and modifications may be made therein as will be, apparent to a person skilled in the art. The invention is therefore to be limited only in accordance-with the following claims when interpreted in view of the prior art.

The invention claimed is:

1. In av photographic sound record apparatus for recording on or reproducing from a film having spaced parallel sound tracks thereon forming a continuous record,'a light source, means for focussing light from saidsource with equal intensity across the entire record area of said. film,

an aperture plate having a single aperture arranged to pass to said film only the rays which register with'a'single sound track, and'means to shift said aperture plate transversely of said film for causing said traysto progressively register with successive sound tracks, said rays being unobstructed during the shift period whereby a continuous uninterrupted sound-record is obtained.

2. In a photographic sound record apparatus for recording on or reproducing from a film having spaced parallel sound tracks thereon formin a continuous record, ,afilm gate, means to feed a film thereover at a uniform speed, a light" source, a lenssystem focussing'light fro'msaid 30 source with equal intensity across the entire record area of the film on said film gate, means supporting said film gate, light source and lens system in fixed position, an aperture plate having a single aperture arranged to pass to said film only the rays which register with a single sound track, and means to shift said aperture plate transversely of said film for causing said rays to progressively register with successive sound tracks. aid rays being unobstructed during the shift period whereby a continuous uninterrupted sound record is obtained.

3. In a photographic sound record apparatus for recording on or reproducing from a film having a plurality of spaced parallel sound tracks thereon, a light source having an elongated light emitting area at least as long as the entire width of the record area of said film, a lens system focussing the light' from'said source with equal intensity across said entire record'area of said film, an aperture plate having a single aperture arranged to pass onlythe rays which register with a single sound track, and means to shift said aperture plate transversely of said film for "causing the rays to progressively register with successive sound tracks, said rays being unobstructed during the shift period whereby a continuous uninterruptedsound record is obtained.

4. In a photographic sound record apparatus for recording sound on a plurality of parallel sound record tracks on a film forming a continuous record, a light source, a lens system focussing light from said source with equal intensity across the entire record area of'said film, an aperture plate between said source and said film having a single aperture to pass only the rays which register with a single sound track,

and means to .shift said aperture plate transversely of said film for causing said rays to pro-. gressively register with successive sound tracks, said rays being unobstructed during the shift period whereby a continuous uninterrupted sound record is obtained.

5. In a photographic sound record apparatus for'recording sound on a plurality of parallel sound record tracks on a film, a light source having an elongated light emitting area at least as long as the entire width of the record area of said film, a lens system focussing light from said source with equal intensity across the entire record area of said film, an aperture plate between said source and said film having a single aperture to pass only the rays which register with a single sound track, and means to shift said aperture plate transversely of said film for causing said rays to progressively register with successive sound tracks, said rays being unobstructed during the shift period whereby a continuous uninterrupted sound record is obtained.

6. In a photographic sound record apparatus for reproducing sound from a film having a plurality of spaced parallel soundtracks thereon forming a continuous record, a light source, a lens system focussing light from said source with equal intensity across the entire record area of said'film, a photoelectric cell positioned to receive said rays after passage through said film, an aperture plate having a single aperture to pass only the rays which register with a single sound track, and means to shift said aperture plate transversely of said film for causing said rays to progressively register with successive sound tracks, said rays being unobstructed during the shift period whereby a continuous. uninterrupted sound record is obtained. I i

7. Ina photographic sound record apparatus for reproducing sound from a film having a plurality of spaced parallel sound tracks thereon forming a continuous record, a light source, a lens system focussing light from said source with equal intensity across the entire record area of said film, a photoelectric cell positioned to receive said rays after passage through said film, an aperture plate between said film and said photoelectric cell having a single aperture to pass rays from a single sound track only, and means to shift said aperture plate transversely of said film for causing said aperture to progressively register with successive sound tracks, said rays 6 being unobstructed during the shift period whereuninterrupted sound record the record area of said film, a lens system focussing light from said source in a narrow band across said record area, a photoelectric cell to receive said light after passage through said film, an aperture plate having a single ,aperture arranged to pass only the rays which register with a single sound track, and means to shift said aperture plate transversely of said film for pro gressively scanning successive sound tracks, said rays being unobstructed during the shift period whereby a continuous uninterrupted sound rec; ord is obtained. 7

9. In a photographic sound record apparatus for reproducing sound from a film having a plurality of spaced parallel sound tracks thereon forming a continuous record, a film gate comprising a housing adapted to receive a photoelectric cell,

means to feed a film over said gate at a uniform,

speed, a light source, a lens system focussinglighting a, plurality of spaced parallel sound tracks from said source with equal intensity across'the entire record area of the film on said gate, an

said aperture plate having a single aperture adapted to pass only the rays from a single sound track, and means to shift said aperture plate transversely of said film for progressively scanning successive sound tracks, said rays being unobstructed during the shift period whereby a continuous uninterrupted sound record is obtained.

10. In a photographic sound record apparatus for recording on or reproducing sound from a film having a plurality of spaced parallel sound tracks thereon, a light source and a photoelectric cell mounted on opposite sides of said film, said light source having elongated elements at least as long as the entire width of the record area of said film, a lens system focussing light from said source across said record area, an aperture plate having a single aperture passing only rays which register with a single sound track, and

means to shift said aperture plate transversely of said film for progressively scanning successive sound tracks, said rays being unobstructed during the shift period whereby a continuous uninterrupted sound record is obtained.

11. In a photographic sound record apparatus for recording a plurality of spaced parallel sound tracks on a film, a light source, a telescope tube gressively scanning successive sound tracks, and 1 means to axially adjust said telescope tube and said aperture plate in unison for adjusting the focus of said rays on said film.

12. In a photographic sound record apparatus for recording on or reproducing from a film having a plurality of spaced parallel sound tracks thereon forming a continuous record, a light source, a lens system focussing light therefrom across the entire record area of said film, an aperture plate having a single aperture to pass only the rays which register with a single sound track, means to shift said aperture plate transversely of said film for progressively scanning successive sound tracks, and a member associ ated with said last mentioned means to' indicate the particular track which is being scanned at any position of said-aperture plate.

13. In a photographic sound record apparatus for recording on or reproducing from a film having a plurality of spaced parallel sound tracks thereon, a light source, a lens system focussing light therefrom across the entire record area of said film, an aperture plate having a single aperture to pass only the rays which register with a single sound track, a ratchet mechanism to progressively shift said aperture plate transversely of said film for scanning successive sound tracks, film-controlled means actuating said ratchet echanism at the end of each sound track, and manual means for adjusting said aperture plate ,toreg'ister with any selected sound track, said rays being unobstructed during the shift period whereby a continuous uninterrupted sound record is obtained. 7

14. In a photographic sound record apparatus for recording on or reproducing from a film havth n, a light source, a lens system focussing lig therefrom across the entire record area of aperture plate'slidably mounted in said housing, sai film, an aperture plate having an aperture 75 to pass only the rays which register with a single sound track, a ratchet mechanism to progressively shift said aperture plate transversely of said film for scanning successive soundtracks, an electromagnet actuating said ratchet mechanism, a conducting strip on said film spaced from I each end of said sound tracks, and means responsive to the influence of said conducting strip to energize said electromagnet when the end of each sound track is reached.

15. In a photographic sound record apparatus for recording on or reproducing from a film having a plurality of spaced parallel soundtracks thereon, a film gate comprising a housing having an annular surface over which the film passes,

means focussing a scanning light on said film for scanning a selected sound track, a film-control mechanism, a conducting strip on said film spaced from each end of said sound tracks, and means responsive to the influence of said conducting strip to actuate said film-control mechamsm.

16. In a photographic sound record apparatus for recording on or reproducing from a film having a plurality of spaced parallel sound tracks ing a plurality of spaced parallel sound tracks thereon, a film gate comprising a housing, having an annular surface over which the film passes,

means focussing a scanning light on said film for scanning a selected sound track, film reversing means, means to shift said light for scanning successive sound tracks, an electric control circuit actuating both of said means in synchronism, and a conducting strip on said film adapted to actuate said electric control circuit'when said strip is in proximity to said film gate.

18. In a photographic sound record apparatus for recording on or reproducingfrom a film having a plurality of spaced parallel sound tracks thereon, a film gate comprising a housing having an annular surface over which the film passes, means focussing a scanning light on said film for scanning a selected sound track, film reversing means, means to shift said light for scanning successive sound tracks, an electric control circuit actuating said film reversing means and said light shifting means in synchronism, and a conducting strip on said film adapted to actuate said electric control circuit when said strip makes contact with said film gate.

19. In a photographic sound record apparatus for recording on or reproducing from a film having a plurality of spaced parallel sound tracks thereon, a film gate having an insulated conducting member over which said film passes, means to feed said film over said gate at a umform speed, means to focus a scanning light on one of said sound tracks, means to reverse the feed of said film, means to shift said scanning light for scanning successive sound tracks, an electric control circuit actuating said film reversing means and said light shifting means in syn'chronism, a conducting strip on said film spaced from the end of said sound tracks, and means actuated when said strip contacts with said conducting member to energize said control circuit for reversing the film and shifting the scanning light in 'synchronism.

20. In a photographic sound record apparatus for recordingon or reproducing from a film having a plurality of spaced parallel sound tracks thereon, a light source, a lens system focussing light from said source with equal intensity across the entire record area of said film, an aperture plate having an aperture adapted to pass only the rays which register with a single sound track, ratchet mechanism to shift said aperture plate transversely of said film for'causing said rays to progressively register with successive sound tracks, said ratchet mechanism comprising a ratchet wheel and pawls cooperating therewith, an arm movable to actuate said pawls, means normally holding said pawls out of engagement withsaid ratchet wheel, spring means for holding said aperture platein any selected position, and manual means for shifting said aperture plate when said pawls are in disengaged position. a

21. In a photographic sound record apparatus for recording on or reproducing fr'oma film having a plurality of spaced parallel sound tracks thereon, a film gate, means to feed a film thereover at a uniform speed, a light source, a lens system focussing light from said source with equal intensity across the entire record area of the film on said film gate, means supporting said film gate, light source and lens system in fixed position, an aperture plate having an aperture adapted to pass only the rays which register with a single sound track, a pivoted arm to control the direction of feed of said film, electromagnetic means to actuate said pivoted arm, electromagnetic means to shift said aperture plate transversely of said film for causing said rays to progressively register with successive sound tracks, an impulse relay adapted at each actuationto reverse the position of said pivoted arm, and to actuate said means for shifting said aperture plate, a space discharge device actuating said impulse relay, means normally supplying a biasing potential to block said space discharge device, and means last-mentioned electromagnetic controlled by the film to change the bias of said space discharge device so as to permit space current to pass for actuating said impulse relay.

22. In a photographic sound record apparatus for recording on or reproducing from a film hav- 7 23. In a photographic sound record apparatus for recording on or reproducing from a film having a plurality of spaced parallel sound tracks thereon, reversible feed means for said film,

scanning means to scan a selected sound track,

shifting means to shift said scanning means from one sound track to the'next, control mechanism 

